* Update spec for MVN-1 and MVN-6.
* Add reduction_axes attribute to MVN-1.
* Fix mean value calculation using ReduceMean.
* Correct reduction_axes attrbute name.
* Restore default value for normalize_variance and eps_mode.
* Remove dafult value for required attributes.
* Correct typeo.
* bulk change `type T` to `type *T*` in spec
* update all `T` which referee to type to use *T* pattern
* get back with `T` where T is dimension
* fix *T*1 -> *T1*
* Make italic types where was no formating
* BatchNormInference specification refactoring
* Address review comments
* Remove he term Transform from definition
* Add title of the paper where this operation is introduced
* Add missing backticks
* Remove redundant information in attribute epsilon range of values
* Refinement of spec
Remove more mentions to transformation to avoid confusion
* Corrected typos and added changes to improve readability
* Use third person to express operation steps
* fix typo in LRN docs
* fix link to reference in LRN doc
* LRN, LRN_IE types alignment with spec
* align LRN ref implementation to plugins behavior
* update LRN docs
* Improve LRN reference implementation performance
* restore LRN constructor with no axes in the input
* apply code format
* revert double->float size_t->int change
* small fix to example in doc
* revert double->float size_t->int in onnx_importer and backend tests
* Changes to docs after review
